Hello everyone,

I have a 100 year old home and am located in northern NJ. Two rooms on the side of our house are in a converted 3 season room (done by previous homeowner 25+ years ago) and the floor is very cold in the winter (the rest of the home is over a finished basement). There is open crawl space on 3 sides below these two rooms (sitting approx. 3 feet off ground) and there is old fiberglass insulation which is covered by plywood. I have already tried spray foaming any openings and seams in the plywood but this has not improved our situation. A few years ago I had a couple spray foam insulation companies come to take a look at our situation and provide an estimate, but did not move forward after one told me I was wasting my money and wouldn't see much improvement. I am now in the middle of redoing my deck and the contractor suggested enclosing the three exposed sides with cinder block and include one vent opening on the eastern side which we could close in the winter. When researching what to do it looks like he also should install a vapor barrier on the ground and sides of the cinder block inside the enclosed crawl space and told him I would want him to include this if we move forward (he said he never put the vapor barrier in before for similar jobs). He also said we do not need to change the insulation we have if enclosing.

My questions are:

1. Will I get a noticeable improvement in the floor temperature of these two rooms like he is promising or am I wasting my money (going to cost me a few grand to do)?
2. Does the above sound like a sound plan or am I opening myself up to other issues in the future. If any steps are missing, what else should be done?
3. Am I better off trying to find a different spray foam insulation company? When researching it seems others have gotten positive results just doing this and not enclosing the crawl space.

Attached is the layout of the first floor (playroom and family room are the two rooms over the crawl space) and a picture from the outside of two of the current openings. Plan also is to find a stone veneer to install in front of the cinder block on the two exposed sides to match the existing foundation.

Thank you for your help!

 

I'm sure someone will be along to answer your actual question, but can I ask what flooring you have in these rooms?
Wood floors and especially carpeting would help also.

 

Hard wood (red oak) with area rugs in each room. We did it a few years ago (used to be tile) and were told it would help but made no impact to the floor temperature.

 

While it would be a shame to cover up wood flooring, if you can't find another solution, I would think thick padding and wall to wall carpeting may be your only option.

 

Thanks for the suggestion. I would rather get to fixing the cause of the issue if it is both possible and worth it...

 

If you have hot water heating you could add PEX underfloor radiant. You would either have to rip out the insulation below and add radiant between the joists (and then re-insulate) or rip out the floor and add heating between the subfloor and a new floor surface. If a change in floor height is OK you could add radiant on top of the existing floor and then a new floor on top of that. Would probably be about 1.5 inches higher.

 

Unfortunately I do not, I have steam heating...

 

Actually it is possible to add a hot water zone on a steam boiler. Pumped connections are made to the wet (bottom) part of the boiler and bypass valves are installed to prevent the water from getting too hot in the zone loop. Similar by pass valve arrangements are often used with hot water radiant heating to keep floor temperatures low (but warm) so I think you could consider it.

 

Thanks. If there is a way to fix the issue this is what we would prefer to do...we definitely are not looking to rip up the floors we recently installed.

 

Go to http://supply house.com and look through their section on radiant heat. There you will find information about how to install PEX tubing between the joists under the floor. I have used their products in two bathrooms and a dining room and the DIY install is not difficult. Their prices are good too.

After installation you can re-install fiberglass insulation DIY or have it spray foamed professionally.

Do an online search for "adding hot water zone to steam boiler" for information about that. Unless you have great plumbing skills you will probably have to get a plumber to do that for you.

 

ok thanks! What about enclosing the space from my original approach? Is this also the right approach?

 

Should not be necessary. I assume the room walls are insulated and there is heat in the rooms so the radiant is just to warm the floors. Enclosing the crawl space will not have much effect once the floor is insulated and it has to be ventilated to prevent other problems so it will not be any warmer than now.

 

So my GC’s suggestion of putting a vent I can close in the winter isn’t a good idea? I don’t know for sure if the floor insulation is adequate or not, but had stopped looking into that route when I had a spray foam company tell me it was not worth doing spray foam insulation a few years ago under the floors...

 

It looks like you have an early 1900s Craftsman/Sears style house with an enclosed porch, which sits 2-3 feet above the ground.

I've seen similar situations (SE Pennsylvania) and the usual fix is to add insulation to seal out air along the perimeter at the base of the room.

I've seen almost everything used to seal the gap; repurposed storm windows, insulation batts, plastic sheeting, old carpet, plastic trash bags packed with styrofoam peanuts, Tyvek, old campaign signs, and piles of mulch.

Best setup I've seen was insulation that fit behind the wood slatting.
A curtain of black landscape plastic glued and tacked to the underside of the porch,
then fiberglass batts glued to the plastic, and a skirt of black plastic about 1 foot wide at the base-
The insulation skirt was tucked up under the porch in summer to let air circulate, in winter it was pulled down so that the plastic and fiberglass batts sealed the gap.

 

Even if you insulate the crawl space, the floors will still be cold. If you install radiant heat in the floor and insulate it then the crawl space can remain open.

Using rigid foam boards (or spray foam) under the floor will provide higher R rating than fiberglass.

 

I would go with more and/or better insulation just under the floor, leaving the crawl space open.

"Everybody" does more and/or better insulation just above the top floor ceiling leaving the attic vents open and that works well, so why not under the lowermost floor?

 

Hi MS, living space over a cold space is a common problem, think bedrooms over a garage. The problem is getting heat down to the floor and keeping it from escaping to the cold space below. 2john has the best approach as it adds the heat where you need it and then follow with super insulation and air sealing below and those floors will be heaven. And the space underneath can remain as it is..

Removing the old fiberglass is almost a must as it is terrible at reducing air circulation and leakage. If you went with just the passive route with spray foam (lots of it) you should see some improvement but adding electric or a zone from your system is foolproof and you would never regret it.

Bud

 

Basically

1- tie the rooms into the main home heating system
2- add permanent insulation to the underside of the floor AND insulate the roof
3- add temporary insulation (plastic sheeting, fiberglass batts, heck lawn and leaf bags stuffed with styrofoam peanuts) around the perimeter of the room to block outside air from getting under the room
4- if there's a basement window or vent INTO the crawl space open it to allow warm air from the basement into the crawl space, and drain cold air out of crawl space.